This game comes from the same developer that brought us "Mono". It is a 2D shooter where you have to take out all the balls that are homing in on you. The balls separate into minor balls once they get hit enough, and then into even smaller balls. Sometimes when you get rid of every single ball-piece then you get a power-up.
This sounds like "Asteroids", "Mono" and so many other games, but Binary Zoo are famous for their twists of original gameplay. "Mono" had an original gameplay, and of course so does "Duo".
In "Duo" you control TWO guns attached to each other. They are placed different places depending on the level, but mostly in the middle of the level fighting incoming balls from separate sides of a line.
If this sounds easy to you, then please have a game of Duo. The game is simply adrenaline pumping hardcore action waiting to tighten your heartbeat rate.
Curly's World of Freeware has donated a copy of this software and related data to the Classic PC Games catalog. Please visit their website for more information and discussion on this game.